Ok yes after looking further into the template it is a gantry mod which seems to be an issue with jms2win. But just to say IT DOES NOT EXIST is not a good answer as I can use it in the master so IT DOES EXIST. In the slave the template shows in "template manager/templates" but not in "template manager/styles" if this helps you in anyway. I am very new to Joomla and even newer to this multisite module/plugin whatever it is. Its working very good on everything I want apart from this one template for another website. I'll see if they can come up with an answer but if you could help with the install of the gantry stuff or point me in the right direction to get it running in slaves I would appreciate it.

If you have a look in detail in the gantry module, you will see that it uses an "installer" component that DOES NOT exists in the master because Rocket Themes deleted it.

As I have already explained, recently Rocket Themes created a new installer that bypass Joomla installer and that is deleted after used.
So this is normal that it does NOT exists in the master as Rocket Themes had deleted.

If you are using Joomla 2.5, try using the "Extension Manager" / "Discover" but I think it also fail as the RT installer is not present.
Report the issue to Rocket themes.

If the module is defined in the JMS Tool menu, you can install it from the "Tool" menu.
Otherwise, send me the extension in the attachement of an email and I will have a look if I can add its definition in the JMS tool menu.
When this concern a module (not a component), in general, you can just define the extension with the JMS Tool menu as this assume that the content is already present from a component.

Hi,

Ok that's better an explanation. Sorry if I sounded off but now you have said what the issue is I can understand why it's saying what it does.

Thanks

In your orginal question, you didn't mentioned the word Gantry and I can only provide a generic answer.
As soon as you have mentioned the word Gantry, the answer can be more precised because we spoken of a specific case that had a name. (Gantry latest version).